Jean Ranc was a French painter, mainly active in portraiture. He trained under his father Antoine Ranc and his father's former student Hyacinthe Rigaud and served in the courts of both Louis XV of France and (from 1723 onwards) Philip V of Spain. Rigaud's flamboyant style proved to be a major influence on the portrait painters of the 18th century, and Ranc was his most competent pupil and closest disciple. He was received as an Academician in 1703 with portraits of Nicolas de Plattenberg and François Verdier, both now in Versailles, and was listed in the records of the Academy as a portraitist until his death.

Much in demand with the Court, he painted portraits of Louis XIV and each of his grandsons, Louis XV, the Regent Orléans and other leading figures. Philippe of France, Duke of Anjou, who had become King of Spain in 1700, invited a number of artists and artisans to Spain to began a process of reconstruction that was to continue throughout the century. In 1722 Jean Ranc was invited to Madrid to take up the post of First Painter, and as such was placed in charge of all the major artistic projects of the Crown. He painted several portraits of the King and his children and also his second wife Elizabeth Farnese and her family.

He died at Madrid in 1735 when he was succeeded in his post by another Frenchman, Louis Michel Van Loo.